1. Field of the Invention
This invention relates to dissipation of thermal energy generated by an electronic component and more particularly relates to thermal conduction interfacing.
2. Description of the Related Art
One of the primary problems encountered in electronics design is excess thermal energy generated by inefficiencies in the electronic components. For example, as current flows through electric circuitry, some of the electric energy is converted to thermal energy through inefficiencies in the circuit components. Unless the excess thermal energy is dissipated, the electronic components may become increasingly inefficient. The increased inefficiency generates additional thermal energy, and the cycle continues until the component fails.
For example, in an electrical transistor, heat is generated as current flows from one gate of the transistor to another. The heat is generated by inefficiencies in the transistor. Such inefficiencies may include impurities in the silicon, imperfect electron doping, and certain inefficiencies are unavoidably inherent in the device structure and material. As heat is generated, the transistor becomes more and more inefficient, and may eventually fail due to a thermally induced current run-away.
Heat issues are particularly critical in microelectronic circuit packages, such as computer processor chip packages. These microelectronic circuit packages may contain thousands of transistors and other electronic components within a confined space. Additionally, these circuits are typically enclosed in a single chip package for protection and modularity. Consequently, these processor chip packages may reach temperatures of well over 100 degrees Fahrenheit within minutes of operation. Obviously, without a highly efficient method of dissipating the heat generated in such circuits, these microelectronic chip packages would fail to operate properly.
Electronics designers have implemented several different methods of heat dissipation in electronic components. These methods include the use of fans and enclosure venting, heatsink devices, liquid cooling, and the like. However, improvements in electronic technology make possible higher processing speeds and more components within a smaller space. These improvements, while beneficial, complicate the task of heat dissipation. Many of the smaller components are more sensitive to heat. Since more components can be placed in a smaller space, the heat generated is greater. Therefore, the need for improved heat dissipation is ever increasing.
One further method for dissipating heat generated by a heat source includes the use of heat pipes. Heat pipes are typically embodied as a rigid metal tube sealed with a thermally conductive fluid. Typically the heat pipes are filled with water, thermal grease, or other fluid exhibiting a high thermal energy potential. As the fluid is heated by the heat source, it begins to circulate within the heat pipe. In certain instances, the fluid may turn to vapor. As the fluid and vapor circulate, heat is carried from the heat source to a peripheral location. In some systems, the heat pipe carries heat to a set of heat sink fins or to a fan.
As the need to dissipate heat has increased, heat pipes have also been integrated within heat sink devices to further increase the heat dissipation performance of the heat sink. One problem encountered with such integrations is that there is an inefficient thermal coupling between the heat source and the heat pipe through the heat sink surface.
FIG. 1A is a cross-sectional side view of an integrated heat dissipating device 100 of the prior art. The integrated heat dissipating device 100 typically includes one or more heat pipes 110 integrated with a heat sink 106. The heat sink usually includes several fins 108 for dissipating heat to the ambient atmosphere. The bottom surface of the heat sink 106 typically interfaces with the top surface of a heat source 104. The heat source 104 is often a processor chip or other electronic chip package mounted on a circuit board 102. Generally, the heat pipe 110 includes sealed ends 114. The sealed ends 114 enclose a liquid 116 for liquid cooling within the heat pipe 110.
FIG. 1B is a cross-sectional front view of an integrated heat dissipating device 120 of the prior art. Although the integrated heat dissipating device 120 of the prior art may only include a single heat pipe 128 or multiple integrated heat pipes 128. The heat pipes 128 typically have a round cross-section. The integrated heat dissipating device 120 typically includes one or more heat pipes 128 integrated into the body of a heat sink 126. The heat sink 126 typically pulls heat away from a heat source 124 at the interface between the heat source 124 and the heat sink 126. The heat source 124 is typically mounted on a circuit board 122.
The primary problem with the configurations illustrated above is that the heat pipe 110 does not have direct contact with the heat source 104, so the heat pipe 110 does not efficiently cool the heat source 104. Instead, the heat pipe 110 cools only the heat sink 106, however a significant amount of heat may build up at the heat sink to heat source interface. Heat may also gather in the fins 108 or in other portion so of the heat sink 106 that are not in direct contact with the heat pipe 110.
In such systems, the heat pipe typically comprises a rigid material and configured with a round cross-section. The round cross-section is inefficient for capturing heat generated by the heat source, because there is a small surface area presented at the interface between the heat source to heat pipe interface. Round cross-sections additionally create air gaps when the heat pipe is not integrated with a heatsink. These air gaps further restrict thermal coupling efficiency. Thermal grease may be used to fill the air gaps; however it is necessary to apply a compressive load to the thermal grease for efficient thermal conduction. Since the heat pipe is a rigid body, it is difficult to apply an adequate load on the thermal grease.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that facilitate a more efficient thermal interface between a heat source and a heat pipe. Beneficially, such an apparatus, system, and method would provide efficient heat dissipation through effective thermo-coupling between the heat source and the heat pipe. Additionally, the apparatus, system, and method would facilitate the application of a load to thermal grease for further improvements on thermo-coupling between the heat source and the heat pipe.